Author Topic: 1977 750 SS OIL LEAK (Read 4353 times)

jamman718 · « **on:** September 16, 2011, 11:43:22 AM »

Previous post "have you checked the Speedometer cable? Sometimes this will get a crack in it and leak oil down on to the head and into the plug area."

How can this be fixed? Mine has this prob.

MCRider · « **Reply #1 on:** September 16, 2011, 11:55:14 AM »

The speedo cable? Neither it nor the tach cable have oil in them.

Where is your leak exactly?

jamman718 · « **Reply #2 on:** September 16, 2011, 12:10:27 PM »

Actually it's the tach cable and if it's not oil, I don't know what it is.....but it's a fluid of some sort.

jtb · « **Reply #3 on:** September 16, 2011, 12:18:40 PM »

Make sure there aren't 2 oil seals in the valve cover where the tach cable goes.

MCRider · « **Reply #4 on:** September 16, 2011, 01:01:16 PM »

Quote from: jamman718 on September 16, 2011, 12:10:27 PM

Actually it's the tach cable and if it's not oil, I don't know what it is.....but it's a fluid of some sort.

OK, that sounds better.

The oil isn't coming from the cable. Its coming from inside the head. Where the cable plugs into the head there is a round oil seal about 6-8mm in diameter. Not uncommon for those to leak. Get you a new one to understand how it works.

Some have success picking the old one out. Some will thread a very skinny screw into the meat of the seal and puill it out with that. Tappinga new one in is easy, use a deepwell socket or small tube of somesort.

Hope that's it anyway.

jamman718 · « **Reply #5 on:** September 16, 2011, 02:15:51 PM »

That's it! I forgot that a while back some kind of seal sorta rotted out and fell out! Hard to install new one?

MCRider · « **Reply #6 on:** September 16, 2011, 02:23:16 PM »

Quote from: jamman718 on September 16, 2011, 02:15:51 PM

That's it! I forgot that a while back some kind of seal sorta rotted out and fell out! Hard to install new one?

AS JTB mentioned, you'll want to be sure there weren't two, previous owners have been known..., and that if there was just the one, that all of it is out. Look in ther with a light.

If its all clear, you should be able to see the aluminum that it will seat upon, and the drive shaft coming up the center, then just press the new one in, hand pressure should be enough. A tube or socket of the correct size to keep it from getting cocked on the way in.

Eazy peazy.

jamman718 · « **Reply #7 on:** September 17, 2011, 06:39:20 AM »

When searching for a new seal, what is the name of it?

jtb · « **Reply #8 on:** September 17, 2011, 07:05:45 AM »

part # 91256-096-651 just called "oil seal" in the parts fisch @ service honda. About $3+. I'll look in my loose parts box, small chance I may have an extra.

jamman718 · « **Reply #9 on:** September 17, 2011, 08:12:41 AM »

Thanks for the info! Let me know if you find one.

jtb · « **Reply #10 on:** September 18, 2011, 06:39:46 AM »

PM me your address, etc, and I'll send you what I believe is one.

jamman718 · « **Reply #11 on:** September 20, 2011, 08:40:52 AM »

Actually found I can get the correct part from a local shop. Thanks for looking! Do you know of any sources that describe or show installation of the seal? Not sure how it goes on where the cable inserts.....does the cable have to be taken out or does the seal have a slit that allows it to be inserted around the cable?

MCRider · « **Reply #12 on:** September 20, 2011, 08:47:27 AM »

Quote from: jamman718 on September 20, 2011, 08:40:52 AM

Actually found I can get the correct part from a local shop. Thanks for looking! Do you know of any sources that describe or show installation of the seal? Not sure how it goes on where the cable inserts.....does the cable have to be taken out or does the seal have a slit that allows it to be inserted around the cable?

Remove the cable, look down in there to see if any of the old seal still remains. Pick it out with a skinny wood screw or appropriate tool. Run a skinny scredriver around, you should feel the shoulder that the seal will rest on. Put a touch of oil on the new one, inside and out. Offer it to the hole, push in as far as thumb will allow. Don't allow it to cock, push evenly. A 10mm thin, deepwell socket makes a nice drift to tap it the rest of the way home. The cable drive pin will pass thru the center of the seal on its own as the seal is driven down.

I just did mine, piece of cake.

jamman718 · « **Reply #13 on:** September 20, 2011, 08:59:04 AM »

Thanks.....I've never removed the cable.....how is this done?

bjatwood · « **Reply #14 on:** September 20, 2011, 09:13:10 AM »

Just ordered this seal, this morning myself....

Common problem I guess. Mine had been leaking a bit al summer.
Last night gave the synced carbs a real good running (95MPH)

Man these motors sounds good at those kind of RPM's

But upon inspection at the ol homestead, noticed more oil than I wanted coming out of the tach cable seal area...

MCRider · « **Reply #15 on:** September 20, 2011, 09:18:23 AM »

Right where the cable plugs into the rockerbox, top of the engine, where your oil leak should be,

, there is a 5mm screw. Remove that. It should have a dot on it which indicates it is a "JIS" screw. Few people have JIS screwdrivers. Use a #2 Phillips (ISO), but it won't feel quite right. Hopefully the screw will turn easily and it won't be an issue. If the screw doesn't turn easily, use a hammer inpact on it. Actually you could start with the impact driver. Ultimatley you may have to chisel it out, worse case. Once its out the cable just pulls out. I'll get a picture soon.

bjatwood · « **Reply #16 on:** September 20, 2011, 09:46:47 AM »

I'm gonna whack it with my impact hammer first. I never have any luck with these 40 year old phillips head screws!

MCRider · « **Reply #17 on:** September 20, 2011, 09:52:28 AM »

Quote from: bjatwood on September 20, 2011, 09:46:47 AM

I'm gonna whack it with my impact hammer first. I never have any luck with these 40 year old phillips head screws!

The 5mm are harder as they are the JIS style, with the dot on the head, which most driver bits don't really fit as they should. So make sure you're squared up on it and pushed in firmly.

MCRider · « **Reply #18 on:** September 20, 2011, 11:40:24 AM »

Remove this scrw

Pull the cable out

jamman718 · « **Reply #19 on:** September 21, 2011, 06:14:03 AM »

Mine looks a bit larger in diameter; same method?

MCRider · « **Reply #20 on:** September 21, 2011, 06:19:05 AM »

Same screw. Same method.

Rgconner · « **Reply #21 on:** September 21, 2011, 08:25:20 AM »

Quote from: MCRider on September 21, 2011, 06:19:05 AM

Same screw. Same method.

That's what she said!

jamman718 · « **Reply #22 on:** October 04, 2011, 01:56:22 PM »

I just got the seal and it seems like an awefully small hole in the seal for the cable to pass through.....also seems kinda large for the hole in the cover.....I'm sure it's the right one, though by the number description in partshonda.

jamman718 · « **Reply #23 on:** October 06, 2011, 06:11:13 AM »

part # 91256-096-651 just called "oil seal" in the parts fisch @ service honda. About $3+. I'll look in my loose parts box, small chance I may have an extra.

I just got the seal and it seems like an awefully small hole in the seal for the cable to pass through.....also seems kinda large for the hole in the cover.....I'm sure it's the right one, though by the number description in partshonda.

MCRider · « **Reply #24 on:** October 06, 2011, 03:56:07 PM »

Yikes, come on man, look close, in the cam cover, down the hole where the cable came out of. That's where the seal is and the driveshaft sticks up thru it. The drive shaft in the cam cover goes thru the hole in the seal. Pretty small. Then the cable just plugs into the driveshaft. The cable end just touches the seal, maybe not even.

The sealing takes place between the spinning driveshaft and the seal.

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Author Topic: 1977 750 SS OIL LEAK (Read 4353 times)